The United Nations and Arab League mediator on Syria Crisi, Lakhdar Brahimi, has resigned, UN Secretary General Ban Ki-moon said Tuesday.

The United Nations and Arab League mediator on Syria Crisi, Lakhdar Brahimi, has resigned, UN Secretary General Ban Ki-moon said Tuesday.

Standing beside Brahimi at UN headquarters in New York, Ban said he "will relinquish his duties effective May 31."